ON FRIDAY, DECEMBER 4, 2009 AT ABOUT 4:15 PM, I HAD A SUDDEN ACCELERATION INCIDENT WITH MY 2007 TOYOTA PRIUS. I HAD NOT HAD ANY PRIOR DIFFICULTY WITH THIS VEHICLE IN THE APPROXIMATELY 34,000 MILES I HAD DRIVEN SINCE I BOUGHT IT NEW. HOWEVER AT THIS TIME WHEN I TRIED TO BACK THE CAR ABOUT 50 FEET BACKWARDS INTO A MOTEL PARKING SPOT (ACTUALLY THERE WERE 3 OPEN SPOTS IN A ROW), IT RESPONDED VERY ABNORMALLY. I STARTED THE CAR, PUT IT IN REVERSE AND GENTLY APPLIED PRESSURE TO THE GAS PEDAL. INSTEAD OF CREEPING BACKWARDS AT ~5 MPH AS I HAD INTENDED, THE CAR "TOOK OFF" AT ABOUT 30-40 MPH. I STOMPED ON THE BRAKES WITH BOTH FEET AND INITIALLY DIDN'T SLOW DOWN. I FELT AN IMPACT AS MY CAR GRAZED A PARKED VEHICLE. MY CAR JUMPED OVER THE CURB AT THE PARKING LOT EDGE, PASSED OVER SOME SHORT BUSHES AND ENTERED A CULVERT. SOMEHOW I WAS ABLE TO TURN THE CAR AND IT CARVED A 180 DEGREE CURVE AND CAME TO A HALT ABOUT 75 FEET AFTER IT PASSED INTO THE CULVERT. FORTUNATELY I DID MAKE THIS SHARP TURN SINCE THERE IS A 4 LANE HIGHWAY ON THE OTHER SIDE OF THE CULVERT. THERE WERE NO INJURIES AND ONLY SLIGHT DAMAGE TO THE OTHER CAR, BUT AN ESTIMATED $7000 OF BODY DAMAGE TO MY CAR. THE POLICE WERE CALLED AS WELL MY INSURANCE COMPANY. THE OWNER OF THE OTHER VEHICLE WAS LOCATED. MY CAR WAS TOWED TO A LOCAL TOYOTA DEALERSHIP. SINCE THAT TIME, THE LOCAL TOYOTA REGIONAL OFFICE SENT OUT A REPRESENTATIVE WHO INSPECTED MY CAR AND "DURING A ROAD TEST NO ABNORMAL BRAKING OR ACCELERATION PROBLEMS WERE FOUND.